The aim of the project was to clarify the crystal structure of the two-dimensional material vanadium tri-iodide at all temperatures. In the literature, there is ambiguity surrounding the right crystal structure of the compound, with different research groups reporting different crystal structures. To achieve this, I worked collaboratively with a research group to prepare powder sample of the material and use an X-ray diffractometer to obtain the diffraction patterns. Afterwards, I analysed the diffraction patterns and observed a structural phase transition around 80 K, in agreement with all reported studies. The best fitting crystal structures obtained from the project of the measured diffraction patterns at high and low temperatures are rhombohedral R-3 and monoclinic C2/c, respectively. The project also involved theoretically proving that the spin-orbit coupling is responsible for the ferromagnetism in the compound below 50 K.